Stop watch



March 29, 1932. PASTOR 1,851,593

STOP WATCH Filed Feb. 3, 1950 Zlwucm/bo b 177cm; Pasi'or' 3 (BLJKOQWQkTHOMAS PASTOR, OF WATER-BURY, CONNECTICUT STOP WATCH Application filedFebruary 3, 1930. Serial No. 425,494.

This invention relates to Stopwatches and more particularly to thoseembodying the time-piece features.

This invention has for its objects, among others, first, to improve theinstruinentality for holding the sweep hand in the inoperative positionand second, to provide means whereby when the operative mechanism isthrown into mesh a minimum of vibration is imparted to the sweep hand.Other objects are to facilitate a quick and accurate assembly inmanufacture by eliminating one spring and so constructing andpositioning another spring that it does the work both of itself and theeliminated spring in the way also lowering the manufacturing cost.

Reference is made to the drawings which are hereby made a part of thisspecification in which Figure 1 is a plan view of a stopwatch of theclass described with the back removed.

Figure 2 is a view similar to Figure 1 but with the detent leverremoved,

Figure 3 is a section along the line 3-3 of Figure 1 as viewed from theleft, and

Figure is a plan view of the combined tension and friction spring.

Similar numerals of reference indicate like parts throughout thedrawings in which letter A designates the back plate which in the modelshown is a single fiat disc a part of which is cut away (not shown) foraccess to the hairspring. A fine-toothed wheel 1 is mounted to turncontinuously on the third wheel pinion extended through the back plate.This wheel is adapted to mesh with and actuate a fine-toothed pinion 2secured to the needle stafi 15. A detent lever 3 is mounted on and isadapted to oscillate on a pillar 2O fatten-ed in the backplate A. Thelonger arm of the L-shaped detent lever .3 engages the surfaces of acastle cam 4, which has six equidistant caniming surfaces with sixrecesses therebetween and which is rotatably mounted on the back plateA. Mounted beneath and pinned to the castle cam 4t and rotatabletherewith in a clockwise direction only under the control of theclick-spring pawl 5 which meshes with the ratchet teeth, is a ratchet 6having eighteen equidistantly spaced teeth adapted to be engaged in turnby the push lever 7 which has a thumblike extension 7a and aslot 8therein which in cooperation with the setscrew 9 fastened in the backplate, limits the thrust of said lever. A spring 10 secured to the backplate, engages the thumb 7a tending to hold the push lever 7 in theretracted position. A push pin 11 radially mounted in a bushing in thecenterband engages a tab or rightangled extension (not shown) of thepush lever 7. The fiyback lever 12, adapted to oscillate on a pillar onthe backplate has a thumb 152a adapted to engage and interact with thecastle cam t and its recesses, being held in continuous engagementtherewith by a coil spring 13. When the thumb 12a is in a recess asshown in Figure 1, the end 126 engages the heart cam 14-, which is fastto the needle staff 15 which in turn has a bearing in the short arm ofthe detent lever 3. Within the center wheel 17, which rotates betweenthe front plate B and the back plate A. is a small axial cylindricalcore against the lower inner wall of which a small collet 18 fast on theneedle stall 15, rotates. A movement of the short arm of lever 3 inwhich staff 15 has a bearing, carries the pinion into and out of meshwith the fine-toothed wheel 1. The spring 16 both carries th pinion intomeshing position and when the pinion is out of mesh also holds the staff15 and with it the sweep hand 19 against turning. This spring embodiesan improvement over the construction shown in my Patent No. 1,493,125.

Referring to Figure 4- the sprin 16 is preferably made of small steelwire and at approximately the middle has V -shaped bend the inner edgesof which are adapted to press against the staff 15; the end of extensionis adapted to lie a ainst the pillar 20 while the opposite end or thespring has a bentback extension 22 by which the spring 16 is adapted tobe secured to the back plate A by stud 16a fast in the plate. The spring16 as mounted, is always tending to press the staff 15 and with it thepinion 2 into meshing or actuating engagement with the fine-toothedperiphery of the continuously rotating chronograph wheel 1, in thismanner giving to the sweep hand 19 a quick and unretarded start withoutany lost-motion whatsoever. By means of the snug fit of the bearing ofthe detent lever 3 on the pillar 20, which is 53 easily accomplishedwith simple watchmakers tools, I practically eliminate any movement ofthe shaft varies the frictional engagement of the V-bend therewith.Signed at Waterbury, in the county of New Haven and State ofConnecticut, this twentyninth day of January, A. D. 1930.

THOMAS PASTOR.

lost-motion or retarded action and thereby produce. in a simple, andinexpensivmmecha nism a quicker start of the sweep hand than 39 isobtainable in the more expensive stopwatches that possess maorecompl-icated aetuated mechanism. The very quickness of the start,although enhancing the actual recording precision ofthe.instrument,.none-.the less would often cause a vibration of thestaff and a'simultaneous vibration of the .sweephand .19- as it startsto register on the dial, which :vi-bration: often creates 'the -er:roneous-idea in themin'd of the user that a 'gamer loss is beingaccumulated'bythe instrument 1 in starting. This :BIIOIIEOHS ideaSQIlOUSly lessens the utilityof the lnstrument andit isimportanttollimit' the sweep hand. 7 vibration instarting. The stafi 15 lies .be-I.

r tweenthe inner edge's of the V-shaped bend 24:

in the-spring 16. W hen the-staff 15. is moved :awayfrom the-wheelE-lbythe movement of detent lever.8 .in'which it has: a' bearing, the

:sta'fi j presses .harder into the lleshaped porution :QAritl'lCl.pushesthe spring :16 back, in

this manner simultaneously increasing its tension and ,-so the Y inneredges of the EV- shaped portion. grip the staft'xl5 more tightly. Thisfriction grip.- overcomes all. other i tric- :tion and prevents :anyifriction thatmay .be :rleveloped by? the sta'fi' or its-collet 18 fromturning: the sweep hand19- when the actuat- ..-ing wheel .1. and:pinion.;2: are out: of mesh. 'On the other handwhen the stopwatch isstarted and thestafl :15 travels toward the -wheel l the :friction gripof the Vepart. :24: -.-is -lessened gradually, the inner ,edges:.stillsteadying thesta'fi 151 and preventing vi-bra- *tioniasthelpoints of theteeth on the pinion 2 pick up -.the;points1 ofrtheteeth on 1 wheel 1.Obviously in those cases of; engagement when the coincidence of teeth ispoint to point there r :is then the greatest tendency to vibration -.ofthe sta1f1-5 andsimultaneouslyto oscilla- 59 tion of thesweep hand 19inithis position the inner edges of. the- -v"-shaped; part. 124; arestill in sufficient tension contact with the staff- 15 :to prevent?vibration until theteethhave-sunk

